The entire text of the above-referenced disclosure is specifically incorporated by reference herein without disclaimer.
1. Field of the Invention
The disclosed device relates to an auxiliary device for filter exchange in a clean room, and more particularly to an auxiliary device for easily exchanging the filter used in a clean room.
2. Description of Related Art
There is a great demand for a high-purity production environment in the high-tech industries in order to improve the performance and the yield of the production products, wherein the high-precision, high-purity, and asepsis of the production line should be especially and strictly required.
The production environment in the industry is greatly improved benefiting from the introduction of the clean room, which is grouped into several ones like Bio Clean Room (BCR) for preventing the bio-contamination in the field, such as medical field, drug and medicine, food, genetic engineering, etc. and Industrial Clean Room (ICR) for preventing the contamination by particles in the field, such as semiconductor devices industry, precise machinery, new materials industries, etc.
Among various kinds of the above clean rooms, the semiconductor devices fabrication process requires an environment where the Down Stream Laminar Flow Type is formed inside its production line in order to remove particles having an enormous effect on the failure of the performance of semiconductor devices and the production yield.
The Down Stream Laminar Flow Type is good for quickly removing particles generated in the various equipment, materials, facilities, etc. or by operators from the production line.
The construction and the function of the clean room to form Down Stream Laminar Flow thereinside are in detail illustrated referring to FIG. 1.
As shown in FIG. 1, a grating pad 14 having a plurality of holes is installed on a pad frame 12 which is placed a certain height apart from the bottom of the clean room 10, which is divided by the upper side and lower side of the grating pad 14.
Over the grating pad 14, there is installed a production line 16 for accommodating the facility for fabricating semiconductor device (not shown in the figure for its simplicity), and below the grating pad 14, an auxiliary facility for assisting the above fabrication facility (not shown in the figure for its simplicity) and a circulation fan 18 for circulating the air inside the clean room 10.
The circulation fan 18 installed as above induces the air around the upper side and the lower side of the grating pad 14 by means of suction way and guides it to the upper side of the production line 16 through the passage 20 on the sidewall of the clean room 10.
Meanwhile, on the upper side of the production line 16 is installed a plurality of filters 22 for filtering the air which may be contaminated during its moving by being supported by a filter frame 24, and the air over the filter 22 passes through the filter 22 by the pressure state formed by the circulation fan 18 and again induced into the production line 16 in order to form the circulation line.
The air passing through the filter 22 directs downward from the upper side of the production line 16 by the circulation fan 18 and passes the holes of the grating pad 14 vertically moving downward in order to form a Down Stream Laminar Flow.
Therefore, the particles continuously generated inside the production line 16 are induced and discharged out toward the lower side of the grating pad 14 by the above Down Stream Laminar Flow in order to maintain highly pure state inside clean room 10.
In the meantime, when the filter 22 for filtering the air is damaged or contaminated losing its original function, the air which is not filtered through the damaged filter 22 and contaminated is quickly spreading and badly affects the formation of a Down Stream Laminar Flow so as to contaminate the inside the production line 16.
In order to prevent this problem, a regular inspection for the damage and contamination of the filter 22 is made, and the filter 22 to be found damaged is replaced along with a new one with emergency measures.
However, if the filter 22 is replaced while the air is continuously circulated, a large amount of contaminated air is induced into the production line 16 through an open area so as to contaminate the production line 16.
Therefore, according to the conventional method, the exchange of the damaged filter 22 is carried out in such a manner that the end side of the anti-electrostatic vinyl between the filter frame 24 and the pad frame 12 which respectively support the filter 22 to be exchanged, and the grating pad 14 placed under the filter 22 is sealed by using the adhesive member 28, and then the damaged filter 22 is replaced on the upper side of the filter frame 24.
However, as the damaged filter 22 is replaced, the air existing in the upper side of the filter frame 24 moves toward the open area by the pressure difference due to the exchange.
By pressure of the air passing through the anti-electrostatic vinyl 26, and the pressure difference inside the production line 16, the sealed end of the anti-electrostatic vinyl 26 is separated, and through the open area, the induced, non-filtered and contaminated air spreads inside the production line 16 thereby causing the contamination thereof.
Therefore, conventional exchange operation of the filter 22 required the stop of various kinds of facilities installed inside the production line 16. Further, the conventional exchange operation is carried out with the air circulation stopped, which results in a reduction of the productivity and increased time loss, due to the necessity of facility restoration.